I've just finished pointing out to a client the differences between certain lightning protection quotations they had received, as always the price was the first/only thing they checked!

The more expensive quotation worked out to be more economical and was for the correct system for that project, the cheaper priced quotation had not carried out a risk assessment to BSEN 62305:2006 just assumed a level and quantified it in the quotation, but the client did not read the detail!

It could have had some serious consequences if not addressed correctly at the beginning, make sure the companies you approach are qualified, but always read and check the detail!